Feeding of frozen foods in a vertical flow packaging machine



June 13, 1961 E. W. FORTH ETAL FEEDING OF FROZEN FOODS IN A VERTICAL FLOW PACKAGING MACHINE Filed Aug. 8, 1960 5 Sheets-Sheet 1 TTU/PNE Yj June 13, 1961 E. w. FORTH ErAL 2,987,859

FEEDING OF FROZEN FOODS IN A VERTICAL FLow PACKAGING MACHINE Filed Aug. 8, 1960 3 Sheets-Sheet 2 INV EN TOR.

June 13, 1961 E. w. FORTH ErAL 2,987,859

FEEOING OF FROZEN FOODS IN A VERTICAL FLOW PACKAGING MACHINE Filed Aug. 8, 1960 3 Sheets-Sheet 3 INVENTOR. 87 DM/ARD w. FORTH FRANC/5 c/afscM/zo BY $722@ United Safes Pm 2,987,859 Patented June 13, 1961 2,987,859 FEED'ING OF FROZEN FOODS 1N A VERTICAL FLOW PACKAGING MACHINE Edward W. Forth, Longmeadow, and Francis Crescenzo, Springfield, Mass., assignors to Package Machinery Company, East Longmeadow, Mass., a corporation of Massachusetts Filed Aug. 8, 1960, Ser. No. 48,193 Claims. (Cl. 53-177) The present invention relates to improved means for feeding product in a packaging machine, under conditions where frost or moisture condensate might form, as in the feeding of frozen foods.

With the recent availability of plastic films which are capable of retaining their strength and flexibility at low temperatures, packaging frozen foods in bags rather than over-wrapped cartons, has become an ever increasing practice. The use of bags rather than overwrapped cartons is extremely advantageous for the processer of the frozen foods because of the great savings in packaging cost which can be derived.

One of the principal types of package forming and lling machines is the so-called vertical ow machine as disclosed in U.S. Patent No. 1,986,422-Zwoyer. Such machines comprise a vertical drop tube around which the web of wrapping material is folded to form a tube of wrapper material, the longitudinal seam of which is heat sealed. A draw bar grips the lower end of the wrapper tube and transversely heat seals it as it draws the wrapper material downwardly of the drop tube. At this time a charge of product falls through the drop tube and into the wrapper tube above the heat sealed seam thereacross. The draw bar is raised to again clamp the wrapper tube above the charge of product therein and again heat seals a seam across the wrapper tube as it is drawn downwardly. At the bottom of the stroke the previously formed and filled bag is severed and discharged as a completed item. 'I'he cyclical operation of the machine continues with little or no control by the operator other than to supply a hopper with additional product from time to time and to replenish the web of wrapper material when it is exhausted.

There are also vertical flow machines where the drop tube is tilted from the vertical as much as 45 The operation of such machines is essentially 'the same as just described.

Frozen foods usually are at a temperature of about 10 F. when they come to a machine for packaging. This results in moisture condensing on the outside of the drop tube greatly increasing the frictional drag of the wrapper material as it is drawn downwardly of the drop tube. In fact, the frictional drag becomes so great that oftentimes the tube of wrapper material will rupture, resulting in the need for the drop tube to be dried and then a fresh portion of the web of wrapper material wrapped therearound to again initiate operation of the machine. When the wrapper tube ruptures, at least one charge of product will scatter over the inside ofthe machine, thus causing cleaning and maintenance problems which are considerably troublesome. In some cases also, the condensed moisture will freeze and an undesirable buildup of frost will form, primarily on the inside ofthe drop tube and the inside of the funnel leading thereto.

Even though the frozen foods are usually relatively small pellets, as cut corn or peas, they will tend to conglomerate at the entrance to the drop tube and freeze together so that they either block the entrance'toV the drop tube or fall at such a slow rate as to enter the wrapper tube at the wrong portion of the cycle of operation of the draw bars, thereby resulting in improperly vfilled packages.

It is probable that these problems could be overcome if the packaging machine were placed in a room having approximately the same temperature as the frozen foods. However, such a solution is impractical and even if attempted would likely introduce other and more serious problems in theoperation of the machine at such low temperatures.

It is, therefore, the object of the present invention to overcome the above-described problems in packaging frozen foods when using vertical flow packaging machines.

A more specific object of the invention is to prevent the formation of moisture condensate on the drop tube over which the tube of Wrapper material is drawn when packaging frozen foods in a vertical ow packaging machine operating at normal room temperatures.

Another specific object of the invention is to insure the free fall of frozen foods through a drop tube in vertical flow packaging machines so as to reliably drop a charge of product into the wrapper tube in proper timed relation to the cycle of operation of the draw bars.

, The above and other related objects of the invention, as well as the specic features thereof, will be apparent from a reading of the following description of the disclosure found in the accompanying drawings and the novelty thereof pointed out in the appended claims.

In the drawings:

FIG. 1 is an elevation with portions broken away and others in section showing the drop tube and funnel leading thereto,as well as fragments of the volumetric feed cups therefor, as are found in a vertical ilow packaging machine embodying the present invention; Y

FIG. 2 is a section taken generally on line lI-II in FIG. 1;

FIG. 3 is a section taken on line III-II in FIG. 1;

FIG. 4 is an elevation with portions broken away and others in section showing an alternate drop tube mounting; and

FIG. 5 is a section taken on line V-V in FIG. 4.

The drawings for the sake of simplicity show only the fragmentary portions of a Vertical flow packaging machine which are directly associated with the illustrated embodiment of the present inventive concepts. Thus, in FIG. 1, there can be seen the lower portion of a volumetric feed cup 10 which is carried by a plate 12 rotating in the direction indicated by arrows A in FIGS. l and 2. Other cups 10 (not shown) are mounted on the plate 12 and are angularly spaced about its axis of rotation. The cups 10 pass beneath a supply hopper (not shown) so that they are filled with a quantity of product, depending upon the volume of the cups. The bottom of the cup is normally closed off by a closure 14 which is pivotally mounted relative to the plate 12 about a pin 16. More particularly the pin 16 is carried by a bracket 17 suspended from the plate 12 by screws 18. The closure 14 is mounted on a ilat bar 19 which is in turn mounted at one end on the pin 16. A leaf spring 20 is secured to the other end of the bar 19 and rides on a. fixed plate 12 to normally maintain the closure 14 against the bottom of c'up 10.

Beneath the cup 10 is a funnel 24 leading to the top of a compositely formed drop tube 26. The funnel 24 is brazed at its lower end to a flange 28 which in turn is secured by screws 30 to a fixed plate or frame member 32. The composite drop tube 26 comprises an inner tube 34 which is secured by welding or brazing to a flanged hub 36. Concentrically of the tube 34 and spaced therefrom is an outer tube 38 which is secured by brazing to a flanged hub 40. The flanges of hubs 36 and 40 are held together by screws 39 passing through the llange of hub 40 and threaded into the flange of hub 36 whereby the tubes 34 and 38 are held together as a unit. f

' A rectangular split collar 41', comprising collar halves 41, embraces the hub 40 and is held in place thereon by screws 42 (FIG. 3). Screws 43 pass through the collar halves 41 and the anges of hubs 36 and 40 to suspend the composite drop tube 26 from the plate 32. Two heating elements 45 and a thermo-switch 47 are mounted in each collarVY half 41. The heating elements 45 and thermo-switches 47 are connected in conventional fashion to a source of electric current.

In the annular space between the tubes 34 and 38 there is provided a heated electrical blanket 44. The electric blanket 44 is a commercially available item comprising a resistance wire circuit woven or embedded in a rubberlike insulative mat. The blanket 44 is originally rectangularly formed and then wrapped in tubiiform and slipped into the annular space between the tubes 34 and 38. The blanket 44 is just slightly less than coextensve of the height of the composite drop tube 26. The `tube 38 is slotted at 46 to permit electrical connections to made by wires 48 with the resistance unit embedded in the blanket 44. The wires 48 extend to a `suitable source of electrical current not shown, with a variac 50 being provided for controlling the amount of current to, and the temperature of, the electric blanket 44.

Mounted on the xed plate 21 is a bracket 51 to which is secured an air motor 52 having a piston rod 54 and a plunger 56 secured to the outer end thereof. The air motor 52 is connected in a conventional fashion to a suitable source of air pressure by way of conventional sequencing valves which control its operation in predetermined relation to the cycle of the packaging machine, as will be later apparent from the description of operation of the present device.

It will also be noted that an outside former 58 of conventionaldesign is adjacent the upper end of the compositely formed drop tube 26. The web W of wrapper material is drawn over the outside former 58 and wrapped around the outside of the drop tube 26 with its marginal edgesoverlapped at the front thereof. The web W extends heightwise of the dropV tube 26 from the former 58 to the lowerend thereof. Means spaced bel'ow the outside former 58 heat seal the lapped margins of the wrapper to form a seam which completes the formation of the tube of wrapper material. Below the drop tube 26 a draw bar 59 is disposed to grip the lower end of the tube of wrapper material and heat seal a transverse seam thereacross, thereby closing olf the lower end of the wrapper tube. The cups are rotated so that the leaf spring 18 will ride past the edge 60 (FIG. 2) on plate 21 in the proper timed relation so that the closure 14 will swing away and allow product to drop from the cup 10 and fall through the tube 26 into the tube of wrapper material as the draw bars are pulling the tube of wrapper material downwardly along and beyond the drop tube 26. The closure 14 is camrned to a closed position by rod 61 as it rotates beyond the funnel 24. Thereafter the draw bars will release the tube of wrapper material and move upwardly to again clamp the tube of wrapper material and seal a seam or seams across the bottom thereof to complete the forming of the rst package and provide the heat seal seam for the bottom of a successive package. As the draw bars again move down, a new charge of product enters the wrapper tube. Also as the draw bars move down the completed package is severed from the tube of wrapper material and at the bottom of the stroke of the draw bars the severed package is released as the draw bars open. The released package is then discharged from the machine for further handling as may be required.

The'above description of operation essentially is the same as in presently known packaging machines of the vertical ow type, it being one of the objects of the invention to adapt such machines to the packaging of frozen foods with a -minimum of change in the design of existing machines. In this connection reference is made again to the above Zwoyer patent and to a copending U.S. application Serial No. 857,324, filed December 4, 1959, for further details of the operation of the known machine elements which have herein been referred to without being shown in detail in the drawings.

It will be remembered thaty the product being packaged has a temperature rof about"-l0 F. while the machine is in an area at ordinary room temperature. A condition which necessarily results in moisture condensing and frost formation. As has beenmentioned, moisture c'ondensate on the outer surface of th'rdrop'tube 26 would make itrirnpossible to eectively draw the tube of wrapper material therealong.

It has been found that the described drop tube construction enables frozen foods to be fed therethrough without any problems whatsoever in feeding the wrapper tube. YIn this connection it will be noted that the drop tube 26 is'isolarted from all possible sources of moisture condensate. The heated electric blanketvextends heightwise of the drop tube substantially the same distance as does the tube of wrapper material. The outer surface of thel drop tube can therefore be heated to whatever ternperature is necessary to prevent the formation of moisture thereon. It has been found that the temperature of the blanket 44 necessary to attain this end is dependent on ambient temperature and humidity and krate of product feed aswell as product temperature. The variac 50 has been found most eifective for obtaining the proper temperature, which temperature at the' outer surface of the tube 26 is'always below the softening point of whateverjplastic iilm is used for the wrapper tube.

It will also be noted that the tube 26 is suspended below plate 3=2 and protected thereby so that no condensate can fall onto the tubef26 from any point above the plate 32. This in combination with the heated collar 41' secured to the hub 40 effectively isolates the outer sur face of drop tube 26 from any source of condensate which might fall or drip thereon. It has been found thatthe heaters for the collar 41 can be set suflicienly high so that adjustment by means of a Variac or the like is unnecessary.

Not only arethere condensate problems in the feeding and packaging of frozen foods but also there are difficulties in obtaining a free and reliable fall Vof the product through the drop tube as is necessary for an automatic operation where the product must reach the wrapper tube in a minimum time and predictably in timed relation to the cycle of movement of the draw bars,

With this in mind it will be noted that on the approach side of the drop tube (relative to the cup 101) the funnel is sloped at a much lower angle than is conventionally used. Also this portion of the funnel is at and triangular in shape (reference is made to the edges x and y of the triangular portion as seen in Fig. 2). The two adjacent Walls of the funnel are also at triangular portions blended with the approach portion by curved sections. The actual angle of this at, approach portion is 45 which allows the closure 14 to be opened substantially in advance of the cup 10 coming above the tube 26. Product is thus strung out along the approac portion of the funnel 24 and enters the drop tube 26 with a minimum of any tendency to conglomerate thereby assuring that each charge vof productwill arrive at the wrapper tube in proper time. The product is already in motion when it is released from the cup 10 and this motion assists in making certain the product will fall along the ilat portion ofthe funnel in spite of the lower angle being used, Y K l Y Nonetheless the relative warm atmosphere in which the packaging takes place tends to make the frozen product sticky so that they will bunch up or conglomerate at the entrance to the vdrop tube. It will bey noted that the hub 36 has a -tapered bore which is on a steeper angle than any side of the funnel` 24 to facilitate entry of product into the straight wally tube. 34. To further insure against conglomerating of .product at the entrance of tiibe26,A Athe plunger 56-is broughtfto its phantom position during veach cycle of the machine. If there is a jam at the entrance to the drop tube it will be broken by the plunger 56. The plunger is ldisplaced to its lower, jam-breaking position a short while after the closure 14v has opened and just as the last of a charge of product should normally have entered the tube 26. The plunger S6 is then immediately retracted. The action of the plunger prevents any jams forming so that, at worst, there may be an improperly filled package should there be an incipient jam. Even having an improperly lilled package has been found to be a rare occurrence,

It has also been found that a cooperative relation exists between the heated tube 26 and the plunger 56 in that the heated hub 36 is adjacent the unheated funnel 24 which, in solvingone problem tends to create another, in making the frozen product somewhat stickier. The plunger thus enables'the use of heat to overcome condensate problems without any additional jamming problems,

Referring next to FIGS. 4 and 5, an alternate form of the invention will now be described. It will be seen that the droptube 26 (FIG. 4) is the same as before, comprising an inner tube 34', an outer tube 38 with an electric blanket 44 disposed in the annular space therebetween. The tube 34 is brazed to a iianged hub 36 and the tube 38 is brazed to a flanged hub 40. These elements are all suspended from a fixed frame plate 32. Other parts corresponding to those previously described are likewise identified by primed referenced characters without further description.

It will be seen that the heated collar previously secured to the hub 40 (FIG. 1) has been omitted. Instead, the hubs 36 and 40 are heated by a member 85 which is, in elect, a portion of the funnel throat leading to the drop tube. 'Ihe member 85 rests on the plate 32 and is held in place by screws 43 which pass through the flanges of hubs 36', 40 and the plate 32', and are threaded into the member 85. Four heating elements 87 are imbedded in the member 85, as are a pair of thermostats 89. The thermostats 89 and heating elements 87 'are connected to a source of electric current in the same manner as previously described in connection with the heated collar 41'. A funnel '24 is again provided to receivey product discharged from volumetric feed cups and direct it into the drop tube. The funnel 24 is brazed to a ange 28 and rests on a ring 91, The ring 91 is secured to a sheet metal pan 93 which underlies the volumetric feed mechanism and enables this mechanism to be cleaned by a water bath without permitting the parts of the machine therebelow to get wet. This expedient has been found necessary in order to protect parts of the machine from corrosion when the machine is cleaned.

Screws 97 pass through the ange 91, ring 93, and pan 95, and are threaded into the heated member 85 to secure the funnel 24 in place. Screws 99 pass through the flange 91 and are threaded into the ring 85 to permit removal of the heated member 85 without disturbing the funnel 24. This is advantageous when different size parts are being installed for making larger or smaller packages.

With the described arrangement, the member 85 can be heated to a higher degree than the collar 41 previously described, thereby getting greater heat into the throat section leading to the drop tube. This is an area where frost buildup could be particularly critical when operating at high rates of speed, or when operating under unfavorable humidity conditions. The reason higher heats may be used is due to the fact that the member 85 is further displaced from the web of wrapper material passing over the former 58', it being seen disposed above the plate 32 rather than below it, as was the case of the heated collar previously described.

Both forms of the invention have the further advantage of accomplishing the desired ends with a minimum modication of the existing machine structures. It will, of course, be appreciated that the plunger 56 (FIG. 1)

could also be advantageously employed with the Strue-i ture of FIGS. 4 and 5. A

vHaving thus described the invention what is claimed as novel and desired to be secured by Letters Patent ofthe United States is: Y

1. In a vertical flow packaging machine, a vertical composite drop tube around which is folded a web of wrapper material in tubular form and along which the wrapper material is advanced in the operation of the machine, said drop tubecomprising an inner tube rand an outertube spaced therefrom, said tubes being substantially coextensive'in length, and heating means disposed in the annular space between the inner vand outer tubes, said heating means having a height substantially coextensive with the length of wrapper material along the drop tube.

2. In a vertical flow packaging machine, a vertical composite drop tube around which is folded a web of wrapper material in tubular form and along which the wrapper material is advanced in the operation of the machine, said drop tube comprising an inner tube and an outer tube spaced therefrom, said inner and outer tubes being substantially coextensive in length, and a tubufor-m electric blanket disposed in the annular space between the inner and outer tubes, said electric blanket having a height substantially coextensive with the length of wrapper material along the drop tube.

3. In a vertical flow packaging machine, a vertical composite drop tube around which is folded a web of wrapper material in tubular form and along which the wrapper material is advanced in the operation of the machine, said drop tube comprising an inner'tube having a anged hub secured to the upper end thereof and an outer tube spaced from said inner tube and having a flanged hub telescoped over the hub of the inner tube, said inner and outer tubes being substantially coextensive in length, and a tubuforrn electric blanket disposed in the annular space between the inner and outer tubes, said electric blanket having a height substantially co-extensive with the length of wrapper material along the drop tube, said outer tube having an opening therethrough adjacent its upper end, and means extending through said opening for connecting the electric blanket to a suitable source of electric current.

4. A drop tube as in claimv 3, wherein means are pro-v vided for varying the ow of current to said electric blanket to thereby adjust the temperature of said drop tube.

5 In a vertical flow packaging machine, a horizontally disposed plate having a -hole therethrough, a vertical composite drop tube around which is folded a web of wrapper material in tubular form and along which the wrapper material is advanced in the operation of the machine, said drop tube lying wholly within the vertical outline of said plate and disposed centrally of the opening therethrough for the passage of product through the interior of said drop tube, said drop tube comprising an inner tube having a flanged hub secured to the upper end thereof and an outer tube spaced from said inner tube and having a flanged hub telescoped over the hub of the inner tube, said inner and outer tubes being substantially coextensive in length, means holding the anges of said tubes together and securing the flange of the inner tube against the undersurface of said plate, a tubuform electric blanket disposed in the annular space between the inner and outer tubes, said electric blanket having a height substantially coextensive with the length of wrapper material along the drop tube and means for connecting said electric blanket to a suitable source of electric current, and means separate from said electric blanket for heating said anged hubs.

6. Apparatus as in claim 5 wherein the separate heating means comprise a heated collar secured to the hub of the outer tube.

7. Apparatus as in claim 5 wherein the separate heating means comprise a member'disposedabove said horizontal plate.

i 8. vIn' a vertical -flow packaging machine a horizontally disposed plate having a hole therethrough, a vertical composite drop tube around which is folded a web of wrapper material lin tubular Vform and along which the wrapper material is advanced in the operation of the machine, said drop tube lying wholly Within the vertical outline of said plate and disposed centrally of the opening therethrough for the passage of product through the interior of said drop tube, said drop tube comprising an inner tube having a flange hub secured to the upper end thereof and an outer t-ube spaced from said inner tube and having a iianged hub telescoped o'ver the hub of the inner tube, said inner and outer tubes being substantially coextensive in length, means holding the ilanges of said tubes together and means securing the ange' of the inner tube against the undersurface of said plate, a heated collar secured to the hub of the outer tube, a funnel mounted on the upper surface of said plate substantially centrally of the opening therethrough and leading toward said drop tube, a plunger movable from a position above the entrance to said drop tube to a position below the level of said funnel, means for discharging a charge of product into said yfunnel and means tor thereafter moving said plunger to its lower position to insure entry of product into said dropy tube, and a tubu'form electric blanket Vdisposed in the annular space between the inner and outer tubes, said electric blanket having a height substantially coextensive with theV length of wrapper material along the drop tube and means `for connecting said electric blanket to a suitable source of electric current.

9. In a vertical ilow packaging machine, a horizontally disposed plate having a hole therethrough, a vertical composite drop tube around which is -folded a web of wrapper material in tubular form and along which the wrapper material is advanced in the operation of the machine, said drop tube lying wholly within the vertical outline of said plate and `disposed centrally of the opening therethrough for the passage of product through the interior of said drop tube, said drop tube comprising an inner tube having a ilanged hub secured to the upper end thereof and an outer tube spaced from said inner tube and having a flanged hub telescoped over the hub of the inner tube, said inner and outer tubes being substantiallyeoextensive in length, means-'holding the anges of said tubes', together and means securing the flange or the inner tubeagainst the undersur-face of saidY plate, a heated collarsecured Yto the hub of the outer tube, a funnel mounted on the' upper surface of said plate `for receiving products dropped therein from rotating cups, said funnel leading vtowards said drop tube, said funnel comprising a flat triangular portion lying on approximately a `angle with respect to Asaid, plate on the approach side of said Idrop tube, a plunger movable from a position above the entrance to said drop tube to a position below the level ofrsaid yfunneLrneans for moving said plunger to its lower position after product has been `discharged by said cups onto said triangular portion to insure entry of product into said drop tube and a tubuform electric blanket disposed in the annular space between the inner and outer tubes, said blanket having a height substantially coextensive with the length lof wrapper material along the drop tube and means for connecting said electric blanketto a suitable source of electric current. A

10. In a vertical ow packaging machine, a horizontally disposed plate having a hole therethrough, a vertical drop tube around which is folded a web of wrapper material in tubular yform and along which the Wrapper material is advanced in the operation of the machine, means lfor heating said drop tube to prevent the formation of frost or moisture condensate thereon, a funnel mounted on the upper surface of said plate for receiving product dropped therein `frornrotating cups, said yfunnel leading towards said drop tube, said funnel comprising a flat triangular portion lying References Cited in the iile ofV patent UNITED STATES PATENTS 2,237,119 Smith Apr. l, 1941 Tew Sept. 27, 1960 

